JP6668313B2 - Drain pump motor, method of manufacturing the same, and drain pump having the motor - Google Patents

Description

  The present invention relates to a motor used for a drain pump and a method for manufacturing the same, and a drain pump having the motor.

  An air conditioner installed on a ceiling in a room has a drain pan for receiving drain water condensed on the surface of the indoor heat exchanger, and a drain pump (drain pump) for discharging drain water in the drain pan.

  An example of a conventional drain pump is disclosed in Patent Document 1. This drain pump includes a motor section and a pump section. The motor section has a stator circuit section configured by embedding a stator unit in a resin mold section. The stator circuit has a through hole. A pair of upper and lower bearing assemblies are disposed in the through hole. A rotor is disposed between the bearing assemblies, and a drive shaft of the rotor is supported by the bearing assemblies. An impeller (rotating blade) of a pump unit is attached to a drive shaft of the rotor.

JP 2012-127281 A

  In the above drain pump, a pair of upper and lower bearing assemblies are fitted into through holes of a stator circuit portion which is a resin molded product. Generally, the dimensional accuracy of a resin component is often lower than the dimensional accuracy of a metal component. In particular, in a fitting structure (press-fitting structure) in which pressure is applied, the resin is deformed, and positioning accuracy is reduced. For this reason, there is a possibility that a shaft deviation may occur in a configuration in which the bearing is attached to the resin molded product.

  Therefore, an object of the present invention is to provide a motor for a drain pump capable of effectively suppressing a shaft deviation occurring in a configuration in which a bearing is mounted on a resin molded product, a method for manufacturing the same, and a drain pump having the motor.

  In order to solve the above problem, a drain pump motor according to one embodiment of the present invention includes a stator having a resin-made stator mold, a metal motor cover having a peripheral wall portion into which the stator mold is fitted, and A stator-side bearing attached to a stator, a cover-side bearing attached to the motor cover, and a rotor supported by the stator-side bearing and the cover-side bearing, wherein the stator mold is made of a metal stator core; Is embedded, and the stator core is exposed on an outer peripheral surface of the stator mold and is in contact with a peripheral wall portion of the motor cover.

  In the present invention, it is preferable that the stator mold has the stator core and a metal holding member for holding the stator side bearing embedded therein.

  In order to solve the above problems, a drain pump according to another aspect of the present invention includes the drain pump motor, a rotary blade that is driven to rotate by the drain pump motor, and a housing that houses the rotary blade. It is characterized by having.

  In order to solve the above problem, a method for manufacturing a motor for a drain pump according to another aspect of the present invention includes molding a resin stator mold included in a stator so that a metal stator core is exposed on an outer peripheral surface. Then, a stator-side bearing is attached to the stator mold, a cover-side bearing is attached to a metal motor cover, a rotor is supported by the stator-side bearing and the cover-side bearing, and the rotor is supported inside the peripheral wall of the motor cover. The stator mold is fitted so that a peripheral wall portion and the stator core are in contact with each other.

  In the present invention, it is preferable that the stator mold is formed by embedding the stator core and a metal holding member that holds the stator-side bearing.

  In the present invention, the holding member and the stator core are installed in a cavity provided in one mold, and each of the holding members and the stator core is brought into contact with a positioning surface of the mold along a rotation axis direction. It is preferable to fill the resin to form the stator mold.

  According to the present invention, the resin stator mold of the stator has the metal stator core embedded therein and is fitted inside the peripheral wall of the metal motor cover. The stator core is exposed on the outer peripheral surface of the stator mold and is in contact with the peripheral wall of the motor cover. Because of this, the deformation of the resin due to the fitting can be suppressed by the metal stator core being in contact with the peripheral wall of the motor cover. Therefore, it is possible to effectively suppress the axial deviation between the stator-side bearing attached to the stator mold, which is a resin molded product, and the cover-side bearing attached to the motor cover.

It is a figure showing the drainage pump concerning one example of the present invention. FIG. 2 is a sectional view taken along line AA of FIG. 1. FIG. 2 is a diagram showing a motor of the drain pump of FIG. 1. FIG. 4 is a sectional view of a state where the motor of FIG. 3 is disassembled. FIG. 4 is a sectional view illustrating a method for manufacturing the motor of FIG. 3. FIG. 4 is a diagram illustrating a configuration of a modification of the motor in FIG. 3.

  Hereinafter, a configuration of a drain pump according to an embodiment of the present invention will be described with reference to FIGS. The drain pump according to the present embodiment is for discharging drain water accumulated in a drain pan of an indoor unit of an air conditioner to the outside, for example. Of course, the use of this drainage pump is not limited to drainage drainage, but can be used for draining or pumping various liquids.

  FIG. 1A is a front view of a drain pump according to one embodiment of the present invention, and FIG. 1B is a plan view. FIG. 2 is a sectional view taken along the line AA of FIG. 3A and 3B show a motor included in the drain pump in FIG. 1, FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A. FIG. 4 is a cross-sectional view (longitudinal cross-sectional view) along the rotation axis in a state where the motor of FIG. 3 is disassembled.

  As shown in FIGS. 1 and 2, the drainage pump 1 according to the present embodiment includes a housing 10, a cover 20, a rotating blade 30, and a motor 100. In this embodiment, the housing 10, the cover 20, and the rotating blade 30 are made of synthetic resin.

  The housing 10 integrally has a main body 11, a suction pipe 16, and a discharge pipe 18. The main body 11 has a bottom wall 12 having an inverted truncated cone shape and a peripheral wall 13 connected to the outer peripheral edge of the bottom wall 12. The suction pipe 16 extends downward from the center of the bottom wall portion 12 and has a suction port 17 facing downward. The discharge pipe 18 has a discharge port 19 extending laterally (leftward in FIG. 1) from the peripheral wall portion 13 and facing sideways. In this embodiment, the discharge pipe 18 extends linearly to the side, but is not limited to this. For example, the discharge port may be formed in a substantially L-shape or arc shape facing upward. A discharge pipe inlet 15 serving as an inlet to the discharge pipe 18 is provided on the inner peripheral surface 14 of the peripheral wall 13 of the main body 11.

  The housing 10 has a space in which the rotating blades 30 are arranged, and the pump chamber 25 is formed (defined) by surrounding the space together with the cover 20.

  The cover 20 has a substantially cylindrical shape, and its lower end is fitted to the upper opening of the main body 11 of the housing 10, and is attached to the housing 10 by the snap-fit portion 21. A bracket 23 is attached to the upper end of the cover 20 via a locking portion 22. The bracket 23 is provided with a mounting portion 24 for mounting the drainage pump 1 to another device.

  The rotary blade 30 is rotatably accommodated in the pump chamber 25. The rotary blade 30 has a shaft portion 31, a large-diameter blade 33, a small-diameter blade 34, and an annular member 36. The rotary blade 30 has a plurality of large-diameter blades 33 and small-diameter blades 34 formed in a substantially flat plate shape, and in this embodiment, four rotary blades each.

  The shaft portion 31 is formed in a columnar shape, and has a mounting hole 32 at an upper end portion into which the drive shaft 144 of the motor 100 is fitted. The shaft 31 is inserted through the through hole 26 of the cover 20. The plurality of large-diameter blades 33 extend radially from the outer peripheral surface of the shaft portion 31. The plurality of small diameter blades 34 are connected to a radially inner portion at the lower end of each large diameter blade 33. The annular member 36 has an inverted truncated cone shape, and has an opening 37 at the center. The annular member 36 connects the tapered portions at the lower ends of the large-diameter blades 33 to each other. The large-diameter blades 33 are arranged in the pump chamber 25 such that their radially outer ends face the inner peripheral surface 14 of the peripheral wall 13 of the housing 10. The small-diameter blade 34 passes through the opening 37 of the annular member 36 and is inserted into the suction pipe 16.

  The motor 100 as a motor for the drainage pump is housed in the cover 20. The motor 100 includes a stator 120, a rotor 140, a motor cover 150, a stator bearing 161 and a cover bearing 162.

  3A and 3B are a plan view and a longitudinal sectional view of the motor 100. FIG. The stator 120 has a stator mold 121 which is a molded product made of resin. The stator mold 121 integrally includes a substantially disk-shaped upper wall portion 122, a peripheral wall portion 123 extending downward from a peripheral edge of the upper wall portion 122, and a connector portion 124 projecting laterally from the upper wall portion 122. are doing. At the center of the upper wall portion 122, a metal cylindrical holding member 125 for holding the stator-side bearing 161 is embedded by insert molding. A circuit board 129 is also embedded in the upper wall portion 122 by insert molding. The holding member 125 has an open end directed downward. A bobbin 127 integrated with a stator core 126 formed by laminating metal plates is embedded in the peripheral wall portion 123 by insert molding with a copper wire wound in a coil shape. A surface 126 a of the stator core 126 facing outward in the radial direction is exposed in a state in which it is flush with the outer peripheral surface of the peripheral wall portion 123. Wiring 128 is connected to the connector 124. The wiring 128 supplies current to the copper wire wound around the bobbin 127 to excite the stator core 126.

  The rotor 140 has a substantially disk-shaped magnet portion 141 having a magnet. At the center of the magnet part 141, a metal drive shaft 144 is fixed so as to penetrate the magnet part 141. A portion of the drive shaft 144 above the magnet portion 141 is rotatably supported by the stator bearing 161. A portion of the drive shaft 144 below the magnet portion 141 is rotatably supported by the cover-side bearing 162. The magnet part 141 is arranged so as to face the stator core 126 of the stator 120 with a space in the radial direction. Rotor 140 is driven to rotate by the magnetic force of stator core 126 acting on magnet part 141.

  The motor cover 150 is made of a nonmagnetic metal and has a substantially annular plate-shaped bottom wall 151, an outer peripheral wall 152 connected to an outer peripheral edge of the bottom wall 151, and an inner peripheral edge of the bottom wall 151. And an inner peripheral wall portion 153 connected to the inner peripheral wall portion 153. The motor cover 150 can be obtained with high dimensional accuracy by pressing a sheet metal using a press die, for example. The outer peripheral wall portion 152 is fitted with the peripheral wall portion 123 of the stator mold 121 inside.

  The stator-side bearing 161 and the cover-side bearing 162 are, for example, oil-impregnated bearings obtained by compacting and sintering metal powder and then impregnating oil, and are each formed in a substantially cylindrical shape. The stator bearing 161 is press-fitted into the holding member 125 of the stator 120. The cover-side bearing 162 is press-fitted into the inner peripheral wall 153 of the motor cover 150. As the stator-side bearing 161 and the cover-side bearing 162, ball bearings (ball bearings) may be used instead of the oil-impregnated bearings. In a configuration employing a ball bearing, the holding member 125 may be omitted.

  Next, an example of a method for manufacturing the drain pump motor according to the present embodiment will be described with reference to FIG. FIG. 5 is a longitudinal sectional view for explaining the method for manufacturing the motor 100 of the present embodiment.

  First, the stator mold 121 is injection-molded using a mold (a lower mold K1 and an upper mold K2) shown in FIG. The lower mold K1 is a dividable mold configured by combining a plurality of mold parts, or one (single) mold. As shown in FIG. 5B, a holding member 125, a bobbin 127 integrated with a stator core 126, and a circuit board 129 are arranged in a cavity C1 provided in the lower mold K1. At this time, the inner peripheral surface 125a of the holding member 125 is brought into contact with the holding member positioning surface K11 of the lower mold K1 along the rotation axis L direction. Further, the surface 126a of the stator core 126 facing outward in the radial direction is brought into contact with the stator core positioning surface K12 of the lower mold K1 along the rotation axis L direction. Thereby, the holding member 125 and the stator core 126 are positioned in the radial direction with the dimensional accuracy of the lower mold K1. As shown in FIG. 5C, the lower mold K1 and the upper mold K2 are closed, and the resin J is injected and filled. Then, as shown in FIG. 5D, the lower mold K1 and the upper mold K2 are opened, and the stator mold 121 is taken out. On the outer peripheral surface of the peripheral wall portion 123 of the stator mold 121, a surface 126a facing outward in the radial direction of the stator core 126 is exposed.

  Next, the stator-side bearing 161 is press-fitted into the holding member 125 of the stator mold 121 and attached. The cover-side bearing 162 is press-fitted into the inner peripheral wall 153 of the motor cover 150 and attached. Then, the upper end of the drive shaft 144 of the rotor 140 is inserted into the stator-side bearing 161 and the lower end is inserted into the cover-side bearing 162 to rotatably support the rotor 140.

  Then, the peripheral wall 123 of the stator mold 121 is fitted inside the outer peripheral wall 152 of the motor cover 150. At this time, the surface 126a of the stator core 126 facing outward in the radial direction abuts on the inner peripheral surface 152a of the outer peripheral wall portion 152, and the metal portions contact each other, thereby suppressing deformation of the resin due to the fitting. Accordingly, the radial distance D1 between the inner peripheral surface 125a of the holding member 125 and the surface 126a facing outward in the radial direction of the stator core 126, and the inner peripheral surface 152a and the inner peripheral wall 153 of the outer peripheral wall 152 of the motor cover 150. The accuracy of the radial distance D2 from the peripheral surface 153a can be ensured. Therefore, the axis of the stator-side bearing 161 attached to the holding member 125 and the axis of the cover-side bearing 162 attached to the inner peripheral wall 153 of the motor cover 150 can be matched with high accuracy. Can be suppressed.

  As described above, according to the drainage pump 1 of the present embodiment, the metal stator core 126 is embedded in the resin stator mold 121 of the stator 120 of the motor 100, and the outer peripheral wall 152 of the metal motor cover 150 is formed. Fits inside. The stator core 126 is exposed on the outer peripheral surface of the stator mold 121 and is in contact with the outer peripheral wall 152 of the motor cover 150. By doing so, the deformation of the resin due to the fitting can be suppressed by abutting the metal stator core 126 and the outer peripheral wall 152 of the motor cover 150. Therefore, it is possible to effectively suppress the axial deviation between the stator-side bearing 161 attached to the stator mold 121, which is a resin molded product, and the cover-side bearing 162 attached to the motor cover 150.

  In the stator mold 121, a stator core 126 and a metal holding member 125 for holding the stator side bearing 161 are embedded. With this configuration, it is possible to suppress the deformation of the resin when the stator-side bearing 161 is attached to the stator mold 121, and it is possible to more effectively suppress the axial deviation. Further, the holding member 125 can prevent the stator-side bearing 161 and the stator mold 121 from directly touching each other, and can suppress deterioration of the resin due to oil.

  Further, the holding member 125 and the stator core 126 are installed in a cavity C1 provided in one lower mold K1, and the respective holding member positioning surface K11 and the stator core positioning surface K12 along the rotation axis L direction in the lower mold K1 are provided. Contact. Then, in this state, the cavity C1 is filled with resin to form the stator mold 121. As a result, the holding member 125 and the stator core 126 are positioned in the radial direction with the dimensional accuracy of the lower mold K1. Therefore, the accuracy of the radial distance D1 between the inner peripheral surface 125a of the holding member 125 and the surface 126a facing outward in the radial direction of the stator core 126 can be effectively secured.

  The motor 100 of the drain pump 1 according to the above-described embodiment has a configuration in which a cover-side bearing 162 which is a single oil-impregnated bearing is provided on the inner peripheral wall 153 of the motor cover 150. In addition, for example, instead of the cover-side bearing 162, as shown in FIG. 6, a motor 100A having a cover-side bearing 170, which is a bearing unit composed of a plurality of parts, may be adopted. . 6A and 6B show a motor 100A according to a modified example of the above embodiment. FIG. 6A is a plan view, and FIG. 6B is a cross-sectional view taken along line CC of FIG. 6A. . In FIG. 6, the same components as those in the above embodiment are denoted by the same reference numerals. The cover-side bearing 170 of the motor 100 </ b> A has a metal case 171, an oil-impregnated bearing 172 housed in the case 171, and a pressing plate 173 for pressing the oil-impregnated bearing 172 against the case 171. The cover-side bearing 170 is fitted into the inner peripheral wall 153 of the motor cover 150. Since the cover-side bearing 170 accommodates the oil-impregnated bearing 172 in the case 171, the coaxiality between the two bearings can be easily made higher than the configuration of the bearing alone as in the case of the cover-side bearing 162 of the above embodiment. . In such a motor 100A, the same effects as those of the above embodiment can be obtained.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. A person skilled in the art may appropriately add, delete, or change the design of the above-described embodiment, or may appropriately combine the features of the embodiments, as long as the gist of the present invention is provided. Included in the scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... Drainage pump, 10 ... Housing, 11 ... Body part, 12 ... Bottom wall part, 13 ... Peripheral wall part, 14 ... Inner peripheral surface, 15 ... Discharge pipe inlet, 16 ... Suction pipe, 17 ... Suction port, 18 ... Discharge Pipe, 19 ... Discharge port, 20 ... Cover, 21 ... Snap fit part, 22 ... Locking part, 23 ... Bracket, 24 ... Mounting part, 25 ... Pump chamber, 26 ... Through hole, 30 ... Rotating blade, 31 ... Shaft 32, mounting hole, 33, large diameter blade, 34, small diameter blade, 36, annular member, 37, opening, 100, 100A motor, 120, stator, 121, stator mold, 122, upper wall, 123 Peripheral wall portion, 124 connector portion, 125 holding member, 125a inner peripheral surface, 126 stator core, 126a surface facing outward in the radial direction, 127 bobbin, 128 wiring, 140 rotor, 141 magnet portion 144 Drive shaft, 150: motor cover, 151: bottom wall, 152: outer peripheral wall, 152a: inner peripheral surface, 153: inner peripheral wall, 153a: inner peripheral surface, 161: stator side bearing, 162: cover side bearing, 170: cover side bearing, 171: case, 172: oil bearing, 173: holding plate, L: rotating shaft, D1, D2: radial distance, K1: lower die, K11: holding member positioning surface, K12: stator core positioning Surface, K2: Upper mold, J: Resin

Claims (6)

A motor used for a drain pump,
A stator having a resin stator mold,
A metal motor cover having a peripheral wall portion into which the stator mold is fitted,
A stator-side bearing attached to the stator;
A cover-side bearing attached to the motor cover,
A rotor that is supported by the stator-side bearing and the cover-side bearing,
The stator mold is embedded with a metal stator core,
The motor for a drainage pump, wherein the stator core is exposed on an outer peripheral surface of the stator mold and is in contact with a peripheral wall of the motor cover.   2. The motor for a drain pump according to claim 1, wherein the stator mold has the stator core and a metal holding member that holds the stator-side bearing embedded therein. 3. A motor for a drainage pump according to claim 1 or 2,
Rotating blades that are driven to rotate by the drain pump motor,
A housing for accommodating the rotating blades. A method for manufacturing a motor used for a drain pump,
The resin-made stator mold of the stator is embedded and molded so that the metal stator core is exposed on the outer peripheral surface,
Attach a stator side bearing to the stator mold,
Attach the cover side bearing to the metal motor cover,
Rotating the rotor on the stator-side bearing and the cover-side bearing,
A method for manufacturing a motor for a drain pump, comprising: fitting the stator mold inside the peripheral wall of the motor cover so that the peripheral wall and the stator core are in contact with each other.   The method according to claim 4, wherein the stator mold is formed by embedding the stator core and a metal holding member that holds the stator-side bearing.   The holding member and the stator core are installed in a cavity provided in one mold, and the cavity is filled with a resin in a state where each is brought into contact with a positioning surface along a rotation axis direction in the mold. The method according to claim 5, wherein the stator mold is formed.

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